Nice video, but is it not required anymore to perform a test flight after a (744) D-check. Within my company (KL) it was always required to perform a test-flight (with a full cockpit crew + flight test engineer) , because not all flight modes can be simulated 100% on the ground.

Operating a twin over the ocean, you're always one engine failure from a total emergency.

Yeah, that was great. I remember reading about this a few weeks back when it aired. Sure am glad someone UL'd it to Youtube. I also agree that it was very good that they didn't use all manner of noises/gags/effects/personal drama stories that certainly would have been the case if it had been made here. Well done beeb.

I'm not sure about the status of check flights these days, but I think they are a great idea. My first employer never performed test flights after D checks. The only time I witnessed a test flight was after working on a 747SP which was having major problems with its aileron / spoiler system. We spent four whole days with another crew re-rigging the entire system, so I could certainly see the need for a test flight in this case. The only aircraft I was aware of that routinely performed test flights after heavy maintenance was the RAAF 707.

Regards, JetMech

JetMech split the back of his pants. He can feel the wind in his hair.

It is very good to know that aircraft are taken such good care of, let us hope that it never changes, though as discussed in another tech/ops thread - MROs are struggling to find and keep god mechanics because they don't want to pay them more, and so mechanics leave for other jobs. It will be interesting to see how this develops during the next few years.

Yes and no. Many can be (and indeed are) "rolled" into C, B, engine B, A, weekly, and service checks. However, there are some items that require NDT that are nigh on impossible to get to without removing large assemblies and/or airframe sections. It's still best to group these together (especially when their time outs are already closely synched) into a D check or HMV.

Quoting Max Q (Reply 11):Isn't there a way that D checks can be avoided now, with sort of 'heavy' C checks done more often ?

It all depends on what maintenance program the airplane was certified under. The MSG-3 system doesn't absolutely require D-checks. Some aircraft done since the 747-400 don't have D's at all (pure MSG-3 airplanes don't actually have required letter checks, although many are operated that way).

But, once you've certified with D checks in the maintenance plan, it's a huge amount of work to engineer them out. Most of the time, it's not worth it.

Quoting tdscanuck (Reply 13):
It all depends on what maintenance program the airplane was certified under. The MSG-3 system doesn't absolutely require D-checks. Some aircraft done since the 747-400 don't have D's at all (pure MSG-3 airplanes don't actually have required letter checks, although many are operated that way).

But, once you've certified with D checks in the maintenance plan, it's a huge amount of work to engineer them out. Most of the time, it's not worth it.

What is the MSG3 system ?

And another question, I get the impression there are fewer and fewer facilities in N America these days capable of doing a D check on a widebody. Is this true ?

I was most impressed by the fact that BA seemed to keep all maintenance functions in-house at their facility in Wales. Escape slides, toilets, seats, engines, IFE, avionics etc., it all seemed to be done in the one facility.

Regards, JetMech

JetMech split the back of his pants. He can feel the wind in his hair.

And another question, I get the impression there are fewer and fewer facilities in N America these days capable of doing a D check on a widebody. Is this true ?

There's about to be one fewer, when US.. I mean AA closes the AFWMRO. But to answer your question, yes, there are fewer stations specializing in this these days. There are still facilities throughout the US, and more than people think, but the fact is that more and more of this work is going overseas or to central america, where it can be done cheaper. As with anything, the quality and timeliness of the work does vary, but it gets the job done for the airlines this way. In fact, there are many airlines in this country who no longer even do their own C checks, however most of this is still outsourced locally...

Again, this was an awesome show, & I think it's really great BBC didn't try to ham it up.

could be that the flight back to LHR is the test flight. I would think any problems could be worked out by BA at LHR.

Quoting Max Q (Reply 14):
And another question, I get the impression there are fewer and fewer facilities in N America these days capable of doing a D check on a widebody. Is this true ?

Well, some place *can* do them but don't. Delta could do HMVs in Atlanta and maybe MSP but doesn't do them. UA at SFO should be able to do them. I think AA does them on the 777s at TUL. (soon to be in China)

The thing is HKG and PEK are the favorite spots. Will stay that way till the government fixes this mess.

After watching this video it all looks like what I see everyday at work. This was a good show and did a pretty darn good job at showing what it's like on one of these getting a heavy check. I only get to see 767/777 getting heavy checks.

Quoting Starlionblue (Reply 19):AFAIK, CX does most heavy maintenance in Xiamen... Certainly all their cabin upgrades.

He asked about North America, So I'm talking about North American carriers. DL and CO have HMVs done by HAECO. UA has work done in PEK by AMECO. The UA 747 work was done in ICN but i believe it has also moved to AMECO.

Quoting jetmech (Reply 15):I was most impressed by the fact that BA seemed to keep all maintenance functions in-house at their facility in Wales. Escape slides, toilets, seats, engines, IFE, avionics etc., it all seemed to be done in the one facility.

Actually different facilities, but close together, and all owned by BA except the engine shop.
Once the engine needs more than powerplant work, it goes to GE, which is also in Wales and just down the road.

Quoting DeltaL1011man (Reply 18):could be that the flight back to LHR is the test flight. I would think any problems could be worked out by BA at LHR.

It is not a test flight, and an ordinary crew flies it, but occasionaly they will find a problem that needs fixing. But the aircraft is scheduled out of LHR the same evening.

The A320 and B734 operate scheduled pax service when they leave GLA D checks. The B734 may have had a manual reversion test flight before, but only if necessary due elevator of aileron work.

25 DocLightning
: Jetmech, I have a bone to pick with you: I stayed up too late last night watching this and it's ALL YOUR FAULT! Really cool documentary. I have a que